Fuel valve for carburetors



March 21, 1961 o. R. JONES 2,975,798

FUEL VALVE FOR CARBURETORS Filed April 14, 1959 INVENTOR.

OLIVER R. JONES A TTOR NE Y3 2,975,798 FUEL VALVE non CARBURETORS Oliver R. Jones, Rte. 4, Longview, Tex.

Filed Apr. 14, 1959, Ser. No. 806,249

9 Claims. (Cl. 137-445) This invention relates generally to fuel control mechanisms for internal combustion engines and the like, and pertains more particularly to an improved type of mechanism for use within and in conjunction with the float bowl of an internal combustion engine carburetor.

The flow of fuel into the float chamber or bowl of an internal combustion engine carburetor is normally controlled by means of a float mechanism operating directly against a needle valve having an associated seat with which the needle valve is engageable and is movable toward and away therefrom in response to up and down movement of the float as dictated by the level of fuel within the float chamber or bowl. Such systems are conventional and are widely used.

However, this type of fuel level control valve assembly is subject to the disadvantage of offering little resistance to leakage of fuel into the float chamber or bowl above and beyond that which should be normally supplied thereto as dictated by the position of the float and as occurs as a result of abnormal high pressure within the fuel feed line to the float chamber or bowl. That is to say, such systems for controlling the float chamber level of fuel are designed for a predetermined maximum fuel line pressure, and which pressureis normally not in excess of from about three to five pounds per square inch.

, If, for any reason at all, the fuel pump itself delivers a pressure higher than that which is suflicient to cause unseating of the needle valve, excess fuel will be delivered to the float chamber and this will result naturally in an abnormally high level of fuel within the bowl or chamber and a consequent improper functioning of the associated engine. A further common cause of high pressure in the fuel line is due to the fact that. the fuel line normally is subjected to rather elevatedtemperatures and, as a consequence, it is not uncommon for the fuel within the line to boil which, of course, causes an abnormally high pressure within the fuel feed line.

It is therefore of primary concern in connection with the present invention to provide an improved type of control mechanism associated with a carburetor for controlling the level of fuel within the float bowl or chamber thereof which will obviate leakage of fuel into the float bowl or chamber above and beyond that which is demanded by the position of thefloat therein as a result of abnormally high pressure or pressure surges within the fuel feed line.

More specifically, an object of this invention is to provide a mechanism for controlling the intake of fuel into a carburetor float bowl or chamber which will be fully sensitive and responsive to fluctuations in the fuel level and as transmitted thereto by the position of the carburetor float but which will be insensitive to fluctualine which tend to produce forces for unseating the valve associated with the mechanism.

Still more specifically, the present invention contemplates the use of a compound linkage system associated with a float in a float bowl or chamber of a carburetor for internal combustion engines. This compound system incorporates a wedge so constructed and arranged as to resist unseating of its associated valve mechanism due to high pressure surges or conditions in the fuel feed line; but which wedge will, at the same time, be fully responsive and sensitive to fluctuations in the height of the associated float. Thus, as a result, the demand for fuel as reflected by 'the position of the float will be fully satistions and variations of fuel pressure within the fuel feed fled without being affected by abnormal pressures in the fuel intake line.

Further objects of this invention will be seen to include, among others, an economy of construction dictated by simplicity of design without sacrificing effectiveness of the system itself.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings wherein like reference charactersv indicate like parts throughout the several figures and in which:

Fig. 1 is a side elevational view of a conventional type of carburetor having a portion of the float chamber wall thereof broken away to show details of the float control mechanism constructed in accordance with this invention and associated with a conventional type of float within the chamber; 7 7

Fig. 2 is an enlarged sectional view taken through a portion of the carburetor float bowl shown in Fig. l and illustrating more clearly the details of construction of the linkage system associated with the float and the valve mechanism as actuated thereby;

Fig. 3 is a view similar to Fig. 2 but showing the valve in its open position as dictated by the position of the float associated with the linkage system, and A Fig. 4 is a'vertical section taken substantially along the plane of section line 44 in Fig. 2, and showing further details of the valve mechanism and the associated linkage including the wedge which directly operates and actuates the ball valve.

Referring at this time more particularly to Fig. 1, reference numeral 10 therein indicatesin general a carburetor body of conventional construction, the details of which form no part of this invention whatsoever. However, for the purpose of clarity, the carburetor itself includes the usual air intake horn portion 11 which con stitutes the upper portion of the carburetor assembly and which is normally separate from the immediately underlying float chamber or intermediate portion 12' of "the carburetor and which latter portion 12 is separably con- ,nected to the base portion 13 of the carburetor, terminatbody than that shown. This mechanism is responsible for the actuation of the throttle valve which is attached to the shaft 15. The actuation thereof is under the control of the operator of the vehicle with which the internal combustion engine is associated. The linkage mechanism 16, 17 in Fig. 1, shown attached to and actuated in response to rotation of the throttle shaft 15, is for the purpose of overriding an associated fast idle cam 18 movable with the choke valve which is also conventional in modern carburetors. The choke valve is normally automatically actuated by thermostatic or other means and the fast idle cam 18 operates a lever or crank 19 carrying an adjustment screw 20 which, under certain conditions Well known in the art, abuts the ramp 21 of the fast idle cam 18 for automatically controlling the idle speed of the engine through the link member 17. All this is conventional and well understood in the carburetor art.

The upper section 11 of the carburetor includes a dome-like portion 22 which forms the cover or topfor float chamber 23 which has its major portion 24 confined within the intermediate section 12 of the carburetor, and is adapted to contain a predetermined quantity of fuel, that is, an amount of fuel such as to produce a fixed or preset level within the float chamber or bowl. As is also well understood in the carburetor art, proper operation of the internal combustion engine, as occasioned by the proper metering of fuel thereto under any and all operating conditions, is largely dictated by the maintaining of the proper level offuel within the chamber or bowl 23. For the purpose of maintaining the proper and preset level of fuel within the float chamber, there is disposed therewithin a hollow float member or body 25 which is adapted to rise and fall with the level of fuel therewithin.

Referring to Fig. 2, it will be seen that the float body 25 has associated therewith an elongate lever arm 26. This arm 26 has one end portion 27 underlying and rigidly afiixed to the float body 25 with an intermediate portion 28 extending downwardly and outwardly from the float, and terminates in an opposite end portion 29 having a looped portion 30 extending substantially completely around and loosely fitting on a pin 31 carried by the body of the carburetor and projecting through the float chamber. Thus, the float 25 is captive, with relation to the pin or shaft 31 and, through its associated lever arm 26, may rise and fall in accordance with the fuel level within the float bowl or chamber describing an arcuate path having its center coincidental with the longitudinal axis of the pin 31, as will be clearly under stood, and is as is normally conventional in the carburetor art.

Disposed closely adjacent to the pin 31 and rigid with the portion 29 of the lever arm 26 is a generally vertically extending leg 32 located generally at right anglesto the portion 29 and terminating at its upper free end in an apertured eye portion 33. A wedge member indicated generally by the reference character 34 has one end 35 thereof also in the form of an apertured eye with the aperture of the eye 33 coinciding therewith. A rivet or some similar linking element 36 extends through these apertures and pivotally connects the leg 32 to the wedge 34, the purpose of which will be presently apparent.

Referring to Fig. 1, it will be seen that the upper portion 11 of the carburetor body is provided with a boss .device through the inlet nipple 38. In Fig. 2, vthe fuel as delivered to the inlet nipple 38 is discharged into the carburetor float bowl or chamber 23 through the vertical passageway 40, as dictated by the throttling action thereon by the ball valve 41. As more clearly shown in Fig. 3, the lower extremity of the passage 40 is either conically or spherically flared or beveled, as indicated by the reference character 42, to provide a good seat for the spherical ball 41.

In order to contain the ball valve 41 and to guide the wedge 34, the carburetor body is provided with a depending nose indicated by the reference character 45 which is provided with a vertical enlarged bore 46 registering with the smaller passage 40 and of slightly larger diameter than the ball 41 disposed within the upper regions of this bore 46. Further, a transverse bore 47 intersects the upper region of the bore 46, wherein the ball valve 41 is normally contained. The purpose of this transverse bore 47 is to provide for free flow of fuel discharged from the passage 40 into the float chamber 23. The portion 45 is also provided with a transverse slot 50 which loosely but guidably receives the central portion of the wedge 34 therethrough. The wedge itself rests upon a roller or pin 51 carried by the portion 45 of the carburetor body and extends transversely of this portion, but at an angle perpendicular to the direction of the slot 50 through which the wedge 34 projects. The wedge itself. includes a substantially horizontal upper edge surface 52 and a tapered under edge surface 53, so as to provide the wedge with a tapering profile diminishing in height from the end thereof remote from the pivot pin 33.

The relative positioning and disposition of the pin 31, the pivot pin 36, and the pin or roller 51, when the float is at the proper height or level to dictate the fuel shut-off position, is critical. The disposition of these several pins should be such that, in the position of the assemblage as shown in Fig. 2,, an imaginary line extends from the point through the center of the pin 36, and a perpendicular to this line at the center of pin 36 passes downwardly slightly to the left of the center of the pin 31. Stating this another way, an are having its center at point 60 and passing through the center of pin 36 has a tangent at the center of the pin 36 which passes to the left of the center of the pin 31 about which the float arm is pivotally rotatable. The purpose for this will be evident by considering the operation of the device in conjunction with the showing of Fig. 2.

Fig. 2 illustrates that position of the float 25 which will be attained when the fuel within the chamber 23 is at the proper level and under which circumstances no more fuel is desired to be admitted to the chamber 23.

.At this point, the wedge 34 has been moved to the left v to close off the passageway 40 and prevent further entry of fuel into the float chamber 23. Now, if at any time during the position of the parts as shown in Fig. 2

there is an abnormal pressure developed in the passage 40 which would tend to unseat the ball valve 41, it will be evident that such downward pressure of the valve ball 41 against the upper surface 52 of the wedge 34 which tend to rotate the wedge 34 about the point 60, thus tending to lower the left-hand end of the wedge.

However, if the aforementioned relative positionings of the pins 31, 36 and 51 are adhered to or are present under this condition, then instead of forcing the wedge 34 downwardly, the excessive fuel feed pressure will actually tend to lift the arm 26 by virtue of its attempt .to rotate the same in a counterclockwise direction when viewed in Fig.2. But, since this is impossible, no movement of the arm will take place since the wedge 34 is already moved as far to the left in Fig. 2 as it will move,

and such excessive fuel pressure will therefore be ineffective to deliver any more fuel to the chamber23.

.In view of the above, it will be readilyappareut that the device as constructed in accordance with this invention will be fully effective to transmit fuel level variations directly to the valve ball 41 through the medium of the. float assembly 25 and its associated linkage, including the arm 26, the leg 32 and the wedge 34. But, this assembly, at the same time, will resist any tendency for the ball 41 to be unseated due to high pressures in the fuel passageway 40 when the position of the float 25 dictates that no more fuel should be discharged into the float chamber 23. Thus, malfunctioning of the associated internal combustion engine due to abnormal fluctuations and too great a fuel level within the carburetor float bowl or chamber 23 will be completely obviated so long as the aforementioned relative positioning of the pins 31, 36 and 51 is present. Naturally, in order to achieve the proper positioning of these pins relative to each other, the general proportional dimensions as is clearly set forth in Fig. 2 should be adhered to.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim:

1. In a carburetor, a fuel reservoir, having an inlet and an outlet, a float and a linkage system disposed in said reservoir and movable in response to vertical movement of said float, said linkage system including an elongated arm pivotally anchored at one end thereof within said reservoir and having its opposite end moved generally vertically in response to positioning of the float, a valve member controlling said inlet and actuated by said linkage system, the connection between said valve member and the linkage arm being such as to establish an overcenter relationship with the point of pivotal connection between the arm and the reservoir whereby the forces set up in said linkage system by fuel inlet pressure will be opposite to those normally imposed thereon in response to the vertical movement of the float, tending to maintain said valve member in closed position.

2. In a carburetor, a fuel reservoir having an inlet and an outlet, a float disposed within said reservoir and vertically movable therein in accordance with the level of fuel within the reservoir, a linkage system movable in response to vertical movement of said float, a valve member for controlling admission of fuel through said inlet to said reservoir, said linkage system including an arm pivotally anchored at one end thereof to said reservoir and having its opposite end secured to said float, an upstanding leg fastened at its lower end to said arm at a point closely adjacent the point of pivotal connection of said arm to said reservoir, means fixed to the upper end of said leg and engaging said valve member to impart vertical opening and closing movement thereto, said means and said leg being movable between an overcenter relationship with the point of pivotal connection between the arm and reservoir when the valve element is in the closed position and a position on the opposite side of center when the valve element is in the open position, whereby when the valve element is closed, fuel inlet pressure will set up forces in the linkage system opposite to those normally imposed thereon tending to maintain the valve element in closed position.

3. In a carburetor, a fuel reservoir having an inlet and an outlet, a float disposed within said reservoir and vertically movable therein in accordance with the level of fuel within the reservoir, a valve member for controlling admission of fuel through said inlet to said reservoir, a linkage system movable in response to vertical movement of said float, said linkage system including an arm pivotally anchored at one end thereof to said reservoir and having its opposite end secured to said float, an upstanding leg fastened at its lower end to said arm at a point closely adjacent the point of pivotal connection of said arm to said reservoir, means carried by the upper end of said leg and engaging said valve member to impart vertical opening and closing movement thereto, said means and said leg being movable between an overcenter relationship with the point of pivotal connection between the arm and reservoir when the valve element is in the closed position and a position on the opposite side of center when the valve element is in the open position, whereby when the valve element is closed, fuel inlet pressure will set .up forces in the linkage system opposite to those normally imposed thereon tending to maintain the valve element in closed position, said means comprising a wedge element having upper and lower surfaces contained within planes disposed at an acute angle with respect to each other, the upper surface of said wedge being engaged with said valve element within an area thereof intermediate the ends of the wedge element and one end of the wedge being pivotally connected to the upper end of said leg, and a support element fixed within said reservoir and slidably supporting the lower surface of said wedge element.

-4. The assembly as defined in claim 3 wherein said support element includes a fulcrum pin slidably supporting said wedge element.

5. In a carburetor, a fuel reservoir having an inlet and an outlet, a float and a linkage system disposed in said reservoir and movable in response to vertical movement of said float, said linkage system including an elongate arm pivotally anchored at one end thereof within said reservoir and having its opposite end fixed to said float, a valve element controlling said inlet and actuated by said linkage system, the connection between the valve element and the arm being such as to establish an overcenter relationship with the point of pivotal connection between the arm and the reservoir so that forces set up in the linkage system by fuel inlet pressure will be opposite to those normally imposed thereon in response to the vertical movement of the float, tending to maintain the valve element in closed position, such connection including an upstanding leg fixed at its lower end to said arm closely adjacent its point of pivotal connection to leg engaging said valve element.

6. The assembly as defined in claim 5 wherein said said reservoir, and means fixed to the upper end of said means is in the form of a wedge pivotally connected to the upper end of said leg.

7. The assembly as defined in claim 6, including a. cylindrical pin fixed within said reservoir upon which the end of said wedge opposite the leg rests.

8. The assembly as defined in claim 7 wherein said wedge is provided with upper and lower surfaces ,disposed at acute angles with respect to each other, the upper surface of the wedge directly engaging said valve element within an area of such surface intermediate the. ends of the wedge, said pin engaging the lower surface of said wedge adjacent the end thereof which is opposite the end pivotally connected to the leg and beyond the area of the upper surface thereof engaging said valve element.

9. In a carburetor, a fuel reservoir having an inlet and an outlet, a float and a linkage system disposed in said reservoir, the linkage system being movable in response to' vertical movement of said float, said linkage system including an elongate arm pivotally anchored at one end thereof within said reservoir and having its opposite end connected to said float, a valve element controlling said inlet and actuated by said linkage system, the connection between said valve element and the arm being movable between two extremities on either side of center relative to the point of pivoting of said arm, said float being effective to move such connection on opposite sides of center in response to vertical movement of the float tending to move said valve element to closed position, and such connection being urged by fuel inlet pressure upon said valve element towards the overcenter position when said float has moved the connection beyond center so that when the connection has reached the overcenter position, the closedrelation of the valve element is effected and assured by the fuel inlet pressure.

References Cited in the file of this patent UNITED STATES PATENTS Copeman Dec. 16, 1924 

